Magneto equipped gas combustion engines are commonly used to provide traction drive for grass mowing equipment, off road vehicles or other machines. During the typical shutdown of the ignition system and fuel source for these engines, there may be a period of time when excess fuel may not be ignited properly and burned. This occurs because the ignition signal typically may be grounded at the same time as the fuel source is shut off. Excess fuel may pass to the exhaust system where it may ignite and cause an afterbang condition also known as backfire.
U.S. Pat. No. 7,520,264 relates to an ignition circuit designed to provide a time delayed, electrical ground of the magneto signal. This circuit utilizes a triad for alternating current (TRIAC) which may be prone to self-triggering when subjected to fast changing high voltage signals which are very common with magneto signal based ignition systems. For that reason, these circuits cannot effectively support low voltage ignition signals. Additionally, these circuits continuously draw power from the ignition signal (magneto) to create the signal that is used to trigger the TRIAC in the circuit. Drawing power from the magneto signal can negatively impact the engine's performance.
There is a need for an engine ignition shutdown module that can control the time delay between the enabling and disabling of an ignition system and fuel source for an internal combustion engine. There is a need for an engine ignition shutdown module that can interface to high and low voltage, low current signals. There is a need for an engine ignition shutdown module that can reduce or minimize the power from the ignition signal used to perform its functions.